Pump, compressor, motor, or the like



Sept. 19, 1944.

O. B. LJUNGDAHL PUMP, COMPRESSOR, MOTOR, OR THE LIKE Filed May 6, 1941 3 Sheets-Sheet 1 hm N N mm.%\\ i nkih mm mm mm mm Sgpt. 19, 1944.

o. LJUNGDAHL 2,358,721 PUMP, COMPRESSOR; MOTOR, OR THE LIKE I Filed May 6, 1941 3 Sheets-Sheet 2 \Q bmnuwuuhl lxiuhux m w U J 4N l ma 8 xxw w 3 Sheets-Sheet 3 Filed May 6, 1941 Patented Sept. 19, 1944 was UNITED STATES PATENT DFFICE I PUMP, comnnsszgzzroa, OR THE LIKE Oskar Birger Ljungdahl, Stockholm, Sweden Application May 6, 1941, Serial No. 392,143 In Sweden May 22, 1940 6 Claims.

the inner wall of the pump housing, the screwthreads being so arranged relatively to one another that during the rotation of the shaft an entire engagement and sealing between the threads -is always established along a rotating broken line, the diametrically located portions of the threads tightening against one another only with their side-top portions.

Two embodiments of the device according to the invention are illustrated on the accompanying drawings, in which Fig. l is a longitudinal section of one embodiment,

Fig. 2 is a longitudinal section of the embodiment,

Fig. 3 shows a section on the broken line III-IE in Fig. 1,- and Fig. 4 shows a detail.

Referring to the drawings, reference character 2 designates a pump housing, to the inside of which a cylindrlc sleeve 4 is secured by means of screws 3, said sleeve being provided with an internal thread 5. Through the cylindric sleeve there extends a shaft 8, on which a sleeve Ia with a screw 1 is eccentrically mounted, said sleeve'la having a thread .lb corresponding to the thread second 5. The shaft 8 has an eccentric portion 8, on

which part of a sphere 8' is centrally mounted, said spherebeing interposed between a sleeve ll mounted on the shaft 6 and secured to the same by means of a screw III, and a sleeve l3 threaded on to the shaft 8 and secured to the same by meansof a screw l2. In order to equalize the running of the pumpthe sleeves ii and. I! are formed as fly weights Ila andlia on that side which is remote from the eccentric 8, as will be seen from Figs. 1 and 2. On the sphere 9 there is slidably mounted a collar surrounding thesame, one half I5 of which abuts against a shoulder l4 formed on the sleeve la, while the other half It abuts against the first mentioned half. The collar half I! is secured to the sleeve Ia by means of screws ll. Since the diameter 01' the thread lb is smaller than that of the thread 5, the pitch of every point of the thread lb will be greater than that of the corresponding point of the thread 5. The sphere l and the collar surrounding the same allow a certain inclination of the axis of the sleeve la relatively to the shaft 6, whereby the threads 5 and 'lb will substantially engage one another. Reference numeral l8 denotes asealing ring between the pump housing 2 and the sleeve 4, said ring being maintained in its position by means of a ring l9 secured to the sleeve 4 by means of screws 20. At the opposite end (the intake end) of the pump housing a seallng ring 2| is also secured between the pump housing and the sleeve 4 by means of a ring 22. which is secured to the sleeve by means ofscrews 23.

During the rotation of the shaft 8 there will always be an entire engagement between the two threads along a broken line, the contour of which is the same as that of the two threads (see Figs.

1 and 2) and the position of which depends on the position of the eccentric 8.

' At the pressure side of the pump'housing the cover 24 issecured by means of nuts and bolts 25. In the cover there is provided a ball-bearing 26 carrying the shaft 8. At the suction side of the pump housing there is also a cover-21 secured by means of nuts and bolts 28. In the cover there is provided a ball bearing 29 carrying the shaft 6. Reference character 39 indicates an oil casing provided at each ball bearing, to which casing oil is supplied through the nipple 3|. Reference character 32 denotes sealing rings for the oil casing. a I

The fluid enters the suction chamber a through the pipe 33 and a channel 34 in the cover 21 and is forced out from the pressure chamber 36a to the pipe 38 through a channel 35 in the cover 24. The shaft 8 is driven by means, of a belt pulley 31. Reference character 38 denotes a supporting plate. p

In Fig. 2, which shows an embodiment intended to operate as a compressor, the same reference characters are used for the same elements as in Fig. 1. Y

In this case. and whenoil is used as sealing and lubricating means, a blade wheel 40 rigidly secured to the sleeve It in the chamber Ila separates the oil and returns the same to the chamber 34a through a pipe ll. Y

. Owing to the'higher pressure in the chamber 36a the oil is sprayed through a nozzle 42 into the chamber a against a blade wheel rigidly secured to the shaft 6 so that the oil is finely divided to an oil mist which is mixed with the gas, which is of great importance for the capacity of the compressor.

Having now described my invention, what I having a a screw claim as new and desire to secure by Letters Patscrew thread provided in the pump housing the screw threads being so arranged relatively to one another that during the rotation of the shaft a pumping action is effected and an entire engagement and sealing between the threads is always established along a rotating broken line, the diametrically located portions of the threads annular sealing means tightening against one another onlywith their side-top portions, a pipe connecting the pressure chamber with the suction chamber for conveying lubricating oil from one chamber to the other, a first blade wheel provided on the shaft and located in the pressure chamber and arranged to separate oil from the gas as the mixtur of oil and gas leaves the screw threads, the oil being forced by the higher pressure" through said pipe to-the suction chamber and a second blade wheel on said shaft and located in the suction chamber at a position to receive the oil forced through said pipe, whereby the second blade wheel'finely divides the oil so that it mixes with the gas.

2. A machine of the character described, comprising a pump housing having an oil containin suction chamber having a gas inlet at one end and having an oil containing pressure chamber having a gas outlet at the other end, a rotatable shaft havinga portion'arranged in said housing, a screw thread eccentrically and rotatably mounted on the portion of the shaft in the pump housing, acorresponding screw thread provided in the pump housing, the screw-threads being so arranged relatively to one another that during the rotation of the shaft a pumping action is effected and an entire engagement and sealing between the threads is always established along a rotating broken line, the diametrically located portions-of the threads tightening against one another only with their top-side portions, a pipe connecting the pressure chamber with the suction chamber for conveying. lubricating oil from one chamber to the other, a first blade wheel provided on said shaft and located in the pressure chamber and arranged to separate oil from the gas as the mixture of oil and gas leaves the screw threads, the 011 being forced by the higher pressure through said pipe to the suction chamber, a I

second blade wheel on said shaft arranged in-the.

suction chamber at a position to receive the oil forced through said pipe, whereby the second blade wheel finely divides the oil so that it mixes with the gas, and a nozzle at the discharge end of said pipeto spray the oil against the second blade wheel.-

3. In a machine of the character described, a pump housing having an annular wall and having an inlet and an outlet, a rotatable drive shaft portion arranged in th pump housing,

thread eccentrically and rotatably mounted on the portion of the shaft which is arranged in 'the pump housing, a sleeve removably mounted in the pump housing. and having its periphery ensasins the inner surface of said am nular wall, means securing the sleeve to said wail, arranged at the endsbf the sleeve to prevent the passage of fluid between the sleeve and wall, a screw thread provided on the inner surface of the sleeve and corresponding to the screw thread on the'ahaft, the screw threads being so arranged relatively to one another that during the rotation of the shaft a pumping action is effected and an entire engagement and sealing between the threads is always established along a rotating broken line, the diametrically located portions'of the threads sealing against one another only with their side-top portions.

4. A machine of the character described, comprising a pump housing, a rotatable drive shaft having a portion arranged in the housing, a screw thread eccentrically and rotatably mounted on the portion of the shaft which is within the pump housing, a corresponding screw thread fixedly secured in the pump housing and engaging the first mentioned screw thread in such manner as to effect pumping action when the shaft is rotated, a pressure chamber in the housing at one end of the screw threads for receiving lubricating oil and having an outlet, a suction chamber in the housing at the opposite ends of the screw threads and also having an inlet, a blade wheel rotatable with'the shaft and arranged in the pressure chamber for forcing lubricating oil centrifugally, a pipe for leading oil so forced from the pressure chamber and for spraying it into the suction chamber, and a second blade wheel rotatable with the shaft and arranged in the suction chamber to receive the oil so sprayed and to mix it with gas that is to be compressed by the screw threads.

5. A machine of the character described, comprising a pump housing having an inlet and an outlet opposed to each other, a rotatable shaft having a portion extending into the Pump housing, said portion including a cylindrical part arranged eccentricaliy relatively to the axis of the shaft, counter-balance weights fixed to the shaft adjacent to said cylindrical part, a screw thread rotatably mounted on said cylindrical part, a corresponding screw thread fixedly arranged in the pump housing and engaging the first mentioned screw thread, the screw threads being so arranged relatively to one another that during the rotation of the shaft, a pumping action is effected and an entire engagement and sealing between the threads isalways established along a rotating broken line, the diametrically located portions of the threads sealing against one another only with their side-top portions.

6. In a machine of the character described, a pump housing having an inlet and an outlet, a rotatable shaft having a portion arranged in said housing and provided with an eccentrically the shaft a pumping action is effected and an ensealing between the threads along a rotating broken line.

is always established OSKAR BIRGER LTUNGDAHL. 

